73 scamp

First, congrats on your Scamp and welcome to the forum. What a great looking machine!

So the rich condition could just be a carb tuning issue. How can you tell that it's rich? Are you seeing black smoke from the exhaust?

Just as some unsolicited advice: check the date of manufacture on those tires. They might be totally fine but the make/model doesn't ring a bell and my first thought is that they might be old...and therefore a safety issue once you get the 318 pulling a bit better.